diff --git a/src/cpu/sparc/vm/c1_LIRAssembler_sparc.cpp b/src/cpu/sparc/vm/c1_LIRAssembler_sparc.cpp
index 15ca82f28fe3ebbfb0dddc8e0c0f76e412d99210..109f7869220db32cbbc886b6bbe1e263ab63fddc 100644
--- a/src/cpu/sparc/vm/c1_LIRAssembler_sparc.cpp
+++ b/src/cpu/sparc/vm/c1_LIRAssembler_sparc.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -2358,6 +2358,8 @@ void LIR_Assembler::emit_alloc_array(LIR_OpAllocArray* op) {
          op->tmp3()->as_register()  == G4 &&
          op->tmp4()->as_register()  == O1 &&
          op->klass()->as_register() == G5, "must be");
+
+  LP64_ONLY( __ signx(op->len()->as_register()); )
   if (UseSlowPath ||
       (!UseFastNewObjectArray && (op->type() == T_OBJECT || op->type() == T_ARRAY)) ||
       (!UseFastNewTypeArray   && (op->type() != T_OBJECT && op->type() != T_ARRAY))) {
diff --git a/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp b/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp
index f3ba0a2ce02ab83b9d0c701a172976f3e54c3631..2a65de51e5b0c887890fa5c2ab7896474def80fb 100644
--- a/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp
+++ b/src/cpu/x86/vm/c1_LIRAssembler_x86.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1641,12 +1641,14 @@ void LIR_Assembler::emit_alloc_obj(LIR_OpAllocObj* op) {
 }
 
 void LIR_Assembler::emit_alloc_array(LIR_OpAllocArray* op) {
+  Register len =  op->len()->as_register();
+  LP64_ONLY( __ movslq(len, len); )
+
   if (UseSlowPath ||
       (!UseFastNewObjectArray && (op->type() == T_OBJECT || op->type() == T_ARRAY)) ||
       (!UseFastNewTypeArray   && (op->type() != T_OBJECT && op->type() != T_ARRAY))) {
     __ jmp(*op->stub()->entry());
   } else {
-    Register len =  op->len()->as_register();
     Register tmp1 = op->tmp1()->as_register();
     Register tmp2 = op->tmp2()->as_register();
     Register tmp3 = op->tmp3()->as_register();